Let the system (REF ) does not posses finite time escape [1]}. Then integrating both sides of the inequalities in (REF ) and using those results in (REF ) lead to the expressions of \(t_1,t_2,t_3\)  in (REF ). So, for \(t \ge t_{in}+\bar{t}\)
\(\dot{V} & \le -\lambda _{\min }(G)||e_f||^2-\lambda _{\min }(\Omega )||e||^2 \nonumber \\& \le -{\varrho }_m (||e_f||^2+ ||e||^2) ,\) 
